Electric signal system.



No. 789,030. PATENTED MAY 2, 1905.

R. 0. JOHNSTON.

ELECTRIC SIGNAL SYSTEM.

APPLICATION FILED MAR. 30,1904.

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wvemtoz 1 (WM/w P A TENTED MAY 2, 1905.

R. O. JOHNSTON. ELECTRIC SIGNAL SYSTEM.

AFPLIOATION FILED MAE. 30,1904.

3 SHEETS-SHEET -2.

No. 789,030. PATENTED MAY 2, 1905. R. 0. JOHNSTON. ELECTRIC SIGNAL SYSTEM.

APPLICATION FILED MAR; 30,1904.

3 SHEETS-SHEET 3.

win/{Mama UNTTED STATES Patented May 2, 1905.

ROBERT O. JOHNSTON, OF BROOKLYN, NEW YORK.

ELECTRIC SIGNAL SYSTEM.

SPECIFICATION forming part of Letters Patent No. 789,030, dated May 2, 1905.

Application filed March 30, 1904. Serial No. 200,824.

To all whom, it rmty concern:

Be it known that I, ROBERT O. JOHNSTON, a citizen of the United States, residing at Brooklyn, in the county of Kings, State of New York, have invented certain new and useful Improvements in Electric Signal Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to signals for railways,andmore particularly to block-signalsystems, the object of the invention being to provide a construction and arrangement wherein the position of a train in a block will be indicated in the signal-tower automatically, the system including also a semaphore and an automatic locking mechanism which locks the semaphore or signal lever against movement when the block is occupied and releases it when the block is vacated.

Other objects and advantages of the invention will be understood from the following description.

1n the drawings forming a portion of this specification, and in which like characters of reference indicate similar parts in the several views, Figure 1 is a diagrammatic view illustrating a portion of a railway equipped with the present invention. Fig. 2 is a detail view showing the end lever and its electric lock, to-

gether with a portion of a railway and the parts with which the end lever is connected. Fig. 3 is a detail view showing the circuitcloser or push-button that is operated by the train. Fig. 4 is a detail view showing the means for operating the semaphore from the train. Fig. 5 is a detail sectional view of the indicator. Fig. 6 is a detail view showing one of the dials with its index and the electromagnets for progressing the index.

Referring now to the drawings, there is shown a portion of a railway comprising two tracks for accommodating trains traveling in opposite directions, one track including the rails 10, while the other includes the rails 11.

The first-named track is illustrated as divided into two blocks A and B, while the second track is divided into two corresponding blocks O and D. At the mutually-adjacent ends of the blocks A and B is a semaphore-post 12, on which is pivoted a semaphore 13 for movement to indicate an occupied block or clear block in the well-known manner, and at the mutually-adjacent ends O and D is a semaphore-post 4, having mounted thereon a semaphore 15 for movement in the same manner as the semaphore 13, above referred to. Gonsidering the rails 10 to be for trains traveling to the left and the rails 11 for trains traveling to the right in Fig. 1, at the entrance end of the block B and to one of the rails thereof there is pivoted an angular lever comprising an arm 16, having its free end 17 bent at an angle to the remainder thereof and lying adjacent to the tread 18 of the rail, so that the flanges of the wheels that traverse the rail will strike the portion 17 and depress the latter for a purpose to be presently explained. The angular lever comprises a second arm 19, which extends downwardly and is connected with the crank 20 of a crank-shaft 21, with which is connected a rod 22, leading to an angular lever 23, pivoted at the base of the signal-tower 24. A rod is connected to the lever 23 and extends upwardly into the signal-tower, where it is connected with one end of an angular lever 26, the opposite end of which has a handle 27 for manipulating the lever. The crank-shaft 21 has also an arm 28, to which is connected a rod 29, which extends upwardly through the semaphore-post 12 and is attached to the semaphore 13. The parts are so constructed and arranged that when the angular lever 16 is depressed the crank-shaft 21 is moved an angular distance suflicient to draw down on the rod 29 and shift the semaphore 13 to danger position, and when it is desired to return the semaphore to the safe position the crank-shaft 21 may be reversely moved by manipulation of the lever 26.

At each block there is a signal-tower, one of which is indicated at 30 for the block D and one at 24 for the block A. The tower 24 contains the lever 26 for the semaphore 13, while the tower 30 contains a similar lever for the semaphore 15. These towers contain also levers, as indicated, for semaphores at the opposite ends of the blocks.

To indicate the position of a train in a block, each block is provided with the same mechanism, so that a description of one will sulfice for all. In the tower 24 is arranged a dial 31, having pivoted centrally thereof an index 32, of paramagnetic material. The block is divided into a suitable number of sections, and adjacent to the periphery of the dial 31 is arranged a series of electromagnets 33, so spaced that if they are successively magnetized they will cause the index to rotate with a step-bystep movement. At regular intervals along the track there are disposed circuit-closures comprising each a casing 33, in which is mounted a spring-supported contact 34 in position for engagement by a plunger or pushbutton 35 which is mounted in the casing and held normally and yieldably out of contact with the member 34 by means of a spring 36. The push-button or plunger 35 bears against the under side of a rail which has sufficient vertical play to insure depression of the pushbutton 35 into engagement with the member 34 by the weight of a train on the rail. The members 34 are connected all to a wire 37, which is connected, through a battery 38, with one terminal of the winding of each of the electromagnets 33. The opposite terminal of the winding of each electromagnet is connected to the corresponding push-button 35 by means of a wire 39. The successive electromagnets are connected with the successive circuit-closers, so that as a train progresses the electromagnets will be successively energized and the index will jump from one to the next, the circuit-closers being so far apartthat the train will pass onto one circuit-closer before leaving the previous one. Thus at times two mutually-adjacent electromagnets are energized, and the index does not move until the circuit of one electromagnet is broken. It will be noted that in Whichever direction the train be moving the index will correspondingly move over the dial.

In order to hold the semaphore against accidental displacement from the danger position, it is only necessary to hold the lever 26 against movement in the direction to give such motion to the semaphore. The lever 26 is pivoted at the point 40, which is a slight distance above the laterally-directed foot 41 of the lever, and when the lever is shifted to move the semaphore to the safe position the foot 41 is swung downwardly, and to prevent this downward movement a wedge 42 is provided, which is slidably mounted upon a base 43, which carries the notched segment 44, that is engaged by the bolt 45, that holds the lever in its dilferent positions. The wedge 42 is adapted to engage beneath the foot 41 to prevent depression of the latter and is held normally from such position by means of the helical spring 46 ,attached thereto and to the lug 47. The wedge 42 is of paramagnetic material and forms an armature for an electromagnet 48, that is in circuit between the battery 38 and the electromagnets 33, so that so long as any of the push-buttons or circuitclosers are active the electromagnets will be energized and Willhold the wedge in position beneath the foot 41, the electromagnet when initially energized serving to draw the wedge into position beneath the foot. When the electromagnet 48 is deenergized, the spring 46 withdraws the wedge, and the semaphorelever may be then operated. Thus it will be seen that so long as a train is in any part of the block, the semaphore-lever will be held against movement to swing a semaphore, it being remembered that upon entrance of the train the semaphore is automatically swung to danger position by operation of the lever 16. Each switch-tower is provided with two dials and its accompanying mechanism, one for each track, and it will be seen that with the arrangement illustrated the position of a train and its progress in either direction will be indicated What is claimed is 1. The combination with a railway, of a series of circuit-closers spaced along the track, a series of electromagnets corresponding to the circuit-closers and in circuit therewith, a source of electricity with which all of the electromagnets are in circuit, an index movable from one to another of the electromagnets successively as they are successively energized, a semaphore, means including a lever for operating the semaphore and an electrically-operated lock for the lever in circuit with said source of electricity and with all of the circuit-closers.

2. The combination with a railway, of a series of circuit-closers spaced along the track, a series ofelectromagnets corresponding to the circuit-closers and in circuit therewith through a common return, a source of electricity in said common return, an index movable from one to another of the electromagnets successively as they are successively energized, a semaphore, means for operating the semaphore and an electromagnetic locking mechanism for holding the semaphore against movement, in the circuit of the common return.

In testimony whereof I aflix my signature in presence of two witnesses.

ROBERT O. JOHNSTON.

Witnesses:

LOWRY SoMERvILLn, J ACOB RABINEAU. 

